code: def moment(a, moment=1, axis=0, nan_policy="propagate"):
      if nan_policy != "propagate":
          raise NotImplementedError(
              "`nan_policy` other than 'propagate' have not been implemented."
          )
      return da.moment(a, moment, axis=axis)
  
imports: from __future__ import annotations
  import math
  from collections import namedtuple
  import numpy
  import dask.array
  from dask import delayed
  from dask.array.ufunc import wrap_elemwise
  from dask.utils import derived_from
  from scipy import special
  from scipy.stats import distributions
label_desc: Use image node_id 12 for calling a global function with example usage: moment(a, moment, axis, nan_policy) and returns: da